intel/common: fix building error in intel_common.c

Fixes the following building error:

../out_src/src/intel/common/intel_common.c:29:4: error: implicit declaration of function 'free' is invalid in C99 [-Werror,-Wimplicit-function-declarat
ion]
   free(engine_info);
   ^
1 error generated.

Fixes: 5b8b4f78 ("intel/dev: Add engine_class_supported_count to intel_device_info")
Reviewed-by: José Roberto de Souza <jose.souza@intel.com>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/29975>

src/intel/common/intel_common.c

@@ -3,6 +3,8 @@
  * SPDX-License-Identifier: MIT
  */
 
+#include <stdlib.h>
+
 #include "intel_common.h"
 
 #include "intel_engine.h"